This invention relates to blended fuels for internal combustion engines. In one of its aspects this invention relates to the supression of carburetor deposit formation in internal combustion engines. In another aspect of the invention it relates to the use of adsorbent-treated cat cracked gasoline in fuel compositions. In still another aspect of the invention it relates to the preparation of a standard reference fuel for evaluating carburetor detergents for fuel and lubricating oil formulations.
Although it has long been well known in the art to treat gasoline, jet fuel, synthetic gasoline, and other hydrocarbon liquids with the materials such as charcoal, silica-alumina, and other adsorbents to remove oxygen-, nitrogen-, and sulfur-containing compounds it has recently been found that upon adsorbent treatment of cat cracked gasoline a treated material is obtained that is suitable for blending with a fuel composition containing untreated cat cracked gasoline to obtain a fuel that produces an unexpectedly low level of carburetor deposits.
It has also been found that the use of adsorbent-treated cat cracked gasoline as a fuel blending stock provides a means for producing a standard reference fuel for use in evaluating carburetor detergents and lubricating oil formulations by adjusting the level of carburetor deposit formation of a base fuel. The adsorbent-treated cat cracked gasoline can be used to lower the deposit level of a fuel stock and the deposit level of a fuel stock could be adjusted upward by the addition of untreated cat cracked fuel. Another direct means for adjusting the deposit level upward is the addition of primary aromatic amines (anilines) to a base fuel. The addition of the primary aromatic amines would result in a test fuel that would be of low cost and necessary cleanliness and would also produce "typical" carburetor and induction system deposits since the additives would be among those naturally occurring deposit precursors found in gasolines.
It is therefore an object of this invention to provide a method for suppressing the level of carburetor deposit formation in a fuel composition containing untreated cat cracked gasoline. It is another object of the invention to provide a fuel blend suitable for producing low carburetor deposit formation. It is another object of the invention to provide standard reference fuel for evaluating carburetor detergents for fuel and lubricating oil formulations. It is still another object of the invention to provide a method for preparing a standard reference fuel for evaluating carburetor detergents for fuel and lubricating oil formulations.
Other aspects, objects, and the various advantages of this invention will become apparent upon study of this specification and the appended claims.